edt asked...I will answer. Physics you say? The average human female and male have some glaring proportional differences that really matter, SPECIFICALLY from a physics standpoint. You can look all of them up like hip width (which creates a lever arm), center of gravity (lower in women), and, not really last as there are lots of others - foot size.

Foot size, as in length toe to heel or shoe number size is the most important and even affects men with smaller feet with regards to board selection. The foot length is the lever arm that applies the force to the board. The shorter the lever arm, the more applied (by heel or toes) force is needed to resist a given force produced by a set board width. And since women's feet are on average shorter heel to toe than men, they do not have the leverage needed to comfortably edge a board that larger footed person can - even if thet weigh the same or are the same height.

I could go on and on about how you can compensate for this with a larger board, like moving the foot pads closer to the heel side edge, but all of those are trade offs with something else like making toe side impossible.

If you are a man with large feet, you may never have experienced this example of body physics since almost no board is made that is too wide for you. If you have been on a board that is just too wide and you can't hold down the edge, you have experienced what most women and men with small feet have to go through.

But as I said before, you can still make it work. Your speed, range (kitesize), and control are all affected, but typically not detrimental if you are skilled. In my previous post, I was in no way, shape, or form suggesting a beginner ride a blow-up-doll. Try to get the right board for her, sized for her (and her feet, large or small), and get working on techniques.

As far as tall people needing longer boards, well.....that has more to do with body geometry, but still a good deal to do with physics. A longer board allows a wider stance with the same amount of board length from foot pads to board tips. A taller person may not feel comfortable having a narrow stance as it does not allow as much torque to be applied since their legs are in more of a "skinny triangle". A shorter person would have a much more squat position that allows the application of more torque to the board being in a wider triangle. Simply put for a taller person to have his legs at the same angle as a shorter person, their feet need to be placed wider on the board. For that taller person to have the same feeling on the board, their feet still need to be the same distance from the tips of the board - thus necessitating a longer board.

A thought experiment to help you with this is to take a 20ft tall person that weighs 170lbs and try to put them on the board you ride. Not going to work, is it? As you shrink that person to 10ft tall, they may be able to ride your board if they put their foot pads at the tips of the board. But this fix would produce some really bad effects, like trim sensitivity that would have the poor guy nose diving with every forward yank of the kite. This illustrates how foot distance from the tips of the board is just as important as stance width.

I have size 8 1/2 -9 feet, and most TT feel too wide for me. I rode a 34cm OR Mako for years because of it.
I make kite surfboards, and besides taking into consideration our conditions, I adjust length to height due to stance width, and width to weight.

Thanks for the props....and I completely forgot to mention something until I saw your avatar.

Boots such as, wakeboard boots, and snowboardboots/bindings change that dynamic drastically by making the lever arm your calf instead of your heel (kind of). This multiplies the force you can apply to the edge. It does this, not so much by leverage in the boots themselves against the calf, but by how our extremely strong quadriceps take over in place of the calf mussel and tibialis anterior (shin mussel) to change the angle and resist the heel or toe edge forces. Think of it as going from your foot length as the lever to your entire leg up to your hip socket as the lever.

If those boots or bindings are too soft with lots of flex, then a portion of the work is done by the quadriceps, and a portion of the work is still done by the calf mussel and tibialis anterior (shin mussel) - much like straps and pads - only with an assist.

If the boots or bindings are loose with space to rock forwards and back inside of the binding, all the work is done by the calf mussel and tibialis anterior (shin mussel) until contact is made with the boot or binding, then it switches to the work being done (lever arm) by the entire leg.

well explained and seen on the water. I just love seeing guys in boots bragging with a Woo. Put them in straps none of them could jump...Edging and stomping is the mother of Holly jump on flat water.
Not for me tho, my knees are precious

Thanks for the insights guys. It confirmed my suspicions that board length probably scales with height and that width scales with weight. That is also a clever insight on boots. Is that why most wakestyle boards that get used with boots tend to be a bit wider, so that you can edge hard to build pop? Or am I wrong in my perception and the wakestyle/freestyle boards are no wider than the average freeride board?

Again, board width scales up with more weight AND its potential to be levered by large feet (more leverage for wider board) or it scales down with small feet(higher weight can compensate for this so you do not have to reduce width as much).

Or am I wrong in my perception and the wakestyle/freestyle boards are no wider than the average freeride board?

They can be wider with stiffer boots or even the overall additional leverage softer boots give to small feet, but they do not have to be wider. A wakestyle pro (not me) would likely have more to say on this.

the reason that wakeboards are wider is for upwind capability. Freestyle boards have immense rocker, really they are closer to being a board you will find behind a boat or at the wake park than a normal kiteboard. Because of the huge rocker there is only way possible way to be able to get the board to go upwind and that's to make it very wide. Otherwise you would just ride downwind once and you are done. If you put wakeboard boots on a non-wakestyle board then it behaves precisely like the board does in straps (only you are in boots). This is my favorite way to ride! I love getting a board designed for straps and putting boots in it but you have to be a little bit selective first the board has to be a lot stiffer because otherwise thanks to harder pressure you put on the board, it will feel like wet cardboard and second of all you have to make sure that the strength of the board is good enough that you don't pop your inserts or snap the board on a hot landing again because in boots you will be putting more pressure on the board. In straps you can't really put that much pressure on a board because your foot will move around. In boots you are locked in and edge harder pop harder land hotter. It takes me a couple of days to get used to riding in straps if I want to do some board offs, because you have to do everything with less aggression. I would love it if one day they made a board for boots that had basically the same nearly flat rocker as a board with straps but it never happens they always those freestyle boards with as much rocker as a banana.

I would love it if one day they made a board for boots that had basically the same nearly flat rocker as a board with straps but it never happens they always those freestyle boards with as much rocker as a banana.

The new Shinn Ronson will take both straps and boots. I've ridden it with straps - it's more rockered than a Monk but is a freeride/freestyle crossover.